Strokes, or cerebrovascular accidents (CVA), occur suddenly with dramatic, life changing impact for the patient, the family, close colleagues and friends, and in the aggregate for society. Indeed, stroke cost in the US continues aroun~$54 billion/year and is climbing. This SBIR proposal supports the development of two, very closely related manganese-based nanoparticle agents designed to work in conjunction with current MRI plaque characterization techniques to triage patients with ruptured unstable and highly vulnerable carotid plaques to the most appropriate management strategy. These agents have been tuned to provide optimal T1w contrast enhancement and mapping of luminal fibrin in ruptured plaque micro-fissures or angiogenesis expansion below the intimal cap in plaques with advancing vulnerability. In this 3 year, fast-track proposal, Dr. Y. Andrew Wang, a nanomaterials chemist and CEO of Ocean Nano Tech, Inc., serves as the Project Director/Principle Investigator (PD/Pl) and he will be responsible for converting these preclinical laboratory technologies into translatable, sterile, stable agents produced under GLP/GMP for formal preclinical toxicology evaluation and eventual clinical evaluation. Dr. Gregory M. Lanza (Pl) will be responsible for the research refining these laboratory product concepts into viable product candidates with appropriate preclinical process, pharmaceutical and biosafety characterization data and documentation.